Self-pressurizing lubricating pump



June 11, 1957 G. R. MoR'roN SELF-PRESSURIZING LUBRICATING PUMP 2Sheets-Sheet 1 Filed April 11, 1955 @B-e R.

June ll, 1957 G. R. MCRTON SELF-PRESSURIZING LUBRICATING PUMP 2Shets-Sheet 2 Filed April 11, 1955 Y A, :.U//Vf G-ren R. fyon UniteStates Patent O SELF-PRESSURIZING LUBRICATING PUMP Glen R. Morton,Omaha, Nebr., assignor of three-fourths to A. Hiram Sturges, Omaha,Nebr.

Application April 11, 1955, Serial No. 500,485

3 Claims. (Cl. 222-261) This invention relates to hand operated greaseguns of the type in which the plunger is manually operated Withoutleverage, straight hand operated plunger guns being handier in certainuses than compound leverage grease guns, one advantage of the formerguns being that they can be adapted for use where a single plungingmotion is -sullicient whereby the gun can be handled in one hand.

In straight hand operated guns the grease must be passed through a veryconstricted pathway and because of this such guns have heretofore notworked well in cold weather because the grease cannot flow through thislong and constricted pathway when the grease is stift and cold.

The reason the grease passageway is so constricted in this type of gunis because the piston is of a small diameter and long rather than of thelarge diameter and short, the former being necessary because there is noleverage.

Heretofo-.re the return stroke of the plunger in guns of this type hasbeen used only to prepare for the down pumping stroke. It is an objectof this invention to make additional use of the return stroke of theplunger to pump air behind the grease following piston.

Also such guns become air-locked even in summer because air gets intothe reservoir when the reservoir is being lled with grease.

It is therefore an object of this invention to provide a grease gunhaving a sufficient pressure behind the grease following piston to pushair through and out of the gun along with the grease.

Other and further objects and advantages of the present invention willbe apparent from the following detailed description, drawings andclaims, the scope of the invention not being limited to the drawingsthemselves as the drawings are only for the purpose of illustrating away in which the principles of this invention can be applied.

Other embodiments of the invention utilizing the same or equivalentprinciples may be used and structural changes may be made as desired bythose skilled in the art without departing from the present inventionand the purview of the appended claims.

ln the drawings:

Figure 1 is a top plan view of the present invention.

Figure 2 is a greatly enlarged side View in cross section on line 2-2 ofFigure l, showing the components of the present invention at thecompletion of the lubricant pumping movement and an air pumpingmovement.

Figure 3 is an end View in cross section on line 3-3 of Figure 2.

Figure 4 is a further end view in cross section on line 4-4 of Figure 2.

Figure 5 is a partial view in cross section showing the components ofthe present invention at the completion of an air inlet or reversestroke of the plunger and the associated air piston.

Referring in greater detail to the drawings in which like numeralsindicate like parts throughout the several views, the present inventionconsists of a self-pressurizing grease gun or lubricant pump in whichthere is an outer cylinder having a nozzle or dispensing outlet 11 inwhich is a check valve 12 including an O-ring 13, as seen in Figures 2and 5.

A lloating piston 14 within the cylinder 10 subdivides or separates thecylinder 10 into a lubricant chamber 15 and an air chamber 16, thepiston 14 being Ashown in Figure 2 near the limit of its movement intothe air chamber 16. Air pressure in the air chamber 16 will move thepiston 14 into the lubricant chamber 15, forcing the grease or lubricantcontained therein into the port 17 adjacent the one end 18 of an innercylinder 19 which has its one end 18 threaded on a reduced end portion20 of the relief valve body 21, the latter receiving in its other endthe one end of the nozzle or dispensing outlet 11.

The inner cylinder 19 is arranged concentrically with respect to theouter cylinder 10 and has within it a concentrically arranged greaseejection or pump tube 22 connected in communication at one end with thebore of theY relief valve body 21.

The other end of the tube 22 is anchored in a cup washer 23 seated on aresilient gasket 24 positioned within a recess in the adjacent end of apartition plug 25, the latter dividing the cylinder 19 into a lubricantpumping chamber 26 and an air pumping chamber 27.

A plunger 28 reciprocates in the tube 22 to force the lubricant throughthe outlet 11, the lubricant entering the tube 22 by Way of the port 17inthe inner cylinder 19 and by way of another port 29 in the tube 22adjacent the end of the latter where it is connected to the plug 2S.

The other end 30 of the inner cylinder 19 is threadefdly connected tothe end cap 31 through which slides a plunger extension member 32 oftubular construction sealed by the washer 33 in the end cap 31. The oneend 34 of the extension member 32 is seen in Figures 2 and 5 to bethreadedly connected to a piston plug 35 which slides within a piston36, the latter operating in the inner cylinder 19 and having an O-ring37 sealing it for sliding movement therein.

The piston 36 is retained upon the piston plug 35 by the enlarged end 38of the plug 35 which forms a valve seat for another O-ring 39, thelatter closing the passage between the plug 35 and the piston 36 uponoutward or intake stroke of the extension member 32, the air behind thepiston being forced to ow, as indicated by the arrows in Figure 5,around the end and sides of the extension member 32 past the ball checkValve 39' and into the airchamber 16 behind the piston 14.

During this intake stroke, the air ows as shown by the arrows in Figure5 from the passage 40 in the extension member 32 between the reduced end41 of the plunger 28 and the inner wall of the bore 42 in the pistonplug 35.l

From there it flows into the air pumping chamber 27, ready for the nextstroke which will pump air into the air chamber 16.

The reduced end 41 of the plunger extension member 32 has out-struckshoulders 43, one on each side, which engage the end of the plug 35 onthe intake stroke, pulling the plunger 28 in its tube 22 so that a newcharge of lubricant enters the tube 22. On the lubricant pumpingmovement of the plunger 28 and the extension member 32, the face of thepiston plug 35 seats on the check valve Washer 44, as seen in Figure 5,closing communication between the passage 40 and the air pump chamber27.

A handle 45 is secured to the one end of the extension member 32exteriorly of the cylinder 10 and is provided with a passage 46connected in communication with the passage 40. An air filter 47 in thehandle 45 filters the air being admitted to the air chamber 16 throughthe passage 46 and the passage 40 so that no `dirt or grit is permittedbehind the piston 14.

When all of the lubricant contained in the lubricant chamber 15 has beenused, more lubricant may be ad- Pfented .lune 11, 1957` mitted to thelubricant chamber by means of the` conventional plug 48 having aconventional check valve mechanism therein not here illustrated as beinga part of the invention. To let the air out of the chamber 16, theknurled screw 49 having a tiat on one of its sides is loosened,permitting the air to escape as the new charge of lubricant fills thelubricant chamber 15 and moves the piston 14 toward the handle.

Another end cap 50 closes the other end of the cylinder 10 and a nut 51tightens the assembly of the inner and outer cylinders on the valve body21.

In usethe reciprocatory pumping `movement ofthe` plunger 28 as it pumpslubricant to the dispensing outlet` will cause air pumping movements ,ofthe Vpiston plug and its associated piston 36 to cause an increase inpres,- sure in the air chamber 16. When the lubricant chamber 15 is lledwith heavy lubricant, the resistance to flow is the greatest and the airpressure in the air chamber 16 will build up quickly to force the pistonahead to move the lubricant into the tube 22. The air pressure withinthe air chamber 16 will be reduced as the lubricant is pumped from thedispensing outlet.

From the foregoing description, it is thought to be obvious that aself-pressurizing lubricating pump constructed in accordance with myinvention is particularly well adapted for use by Ireason of theconvenience and facility with which it may be assembled and operated,and vit will also be obvious that my invention is susceptible of somechange and modification ywithout departing from the principles andspirit thereof, and for this reason I do not wish to be understood `aslimiting myself to the precise arrangement and formation ofthe severalparts herein shown in carrying out my invention in practice, except asclaimed.

I claim:

1. A lubricating pump comprising a closed cylinder having adispensingoutlet at one end, another cylinder arranged concentricallywithin said rst-named cylinder and having its ends connected to theadjacent ends of said first-named cylinder, a piston surrounding andslidably supported on said second-named cylinder, said ,pistonsubdividing the space between said cylinders into a lubricant chamberand an air chamber, a lubricant pump element mounted in saidsecond-named cylinder `.for movement toward and away from saiddispensing outlet, said lubricant chamber being in communication withsaid secondnamed cylinder adjacent said dispensing outlet and `said airchamber being in communication with said secondnamed cylinder remotefrom said dispensing outlet, and air pump means within saidsecond-,named `cylinder and operatively connected to saidlubricant pumpelement for effecting the movement of said pump element toward and awayfrom said dispensing outlet.

2. A lubricating pump comprising a closedcylinder having a dispensingoutlet at one end, another cylinder arranged concentrically within saidltirst-named `cylinder and having its ends connected to the adjacentends of said rst-named cylinder, a piston surrounding and slidablysupported on said second-named cylinder, said piston subdividing thespace between said cylinders into a lubricant chamber and an airchamber, means in said second-named cylinder subdividing the spacetherein into a lubricant pump chamber adjacent said dispensing outletand an air pump chamber remote from said dispensing element, saidlubricant chamber being in communication with said lubricant pumpchamber `and said air chamber being in communication with said air pumpchamber, a lubricant pump element mounted in said lubricant pump chamberfor movement toward and away from said dispensing outlet, an air pistonmounted within said `air `pump chamber vfor movement toward and away romsaid dispensing outlet and operatively connected to said lubricant pumpelement for effecting the movement of said pump element toward `and away.from said dispensing outlet, and operating means projecting by one endfrom the other end of said first-named -cylinder having its other `endoperatively connected to said air piston for effecting the movement ofsaid air piston toward and away from said dispensing outlet.

3. A lubricating pump comprising a closed cylinder having azdispensingoutlet at one end, another cylinder arranged concentrically within saidtirst-named cylinder and having its ends connected to the adjacent endsof said rstnamed cylinder, a piston surrounding and slidably supportedon said second-named cylinder, said piston subdividing the space betweensaid cylinders into a lubricant chamber and an air chambenvmeans in saidsecond-named cylinder subdividing the space therein into a lubricantpump chamber adjacent said `dispensing outlet, said lubricant chamberbeing in communication with said lubricant pump chamber and Said airchamber being in communication with said air pump chamber, a lubricantpump element mounted in said lubricant pump chamber for movement towardand away from said dispensing outlet, an air piston mounted within saidair pump cylinder for reciprocal movement toward and away `from saiddispensing outlet and operatively connected to said lubricant pumpelement for effecting the movement of said pump element toward and awayfrom said dispensing outlet, and handle means exteriorly of saidfirst-named cylinder having an end portion projecting thereintooperatively connected to said `air piston for effecting movement of thelatter, said handle means being provided with a passagefor aircommunicating with said air pump chamber.

References Cited in the tile of this patent UNITED STATES PATENTS

